Long medium

ABSTRACT

A plurality of marks ( 11 ) equidistantly provided on both side edge parts ( 1   a ) of a long medium ( 1 ), a plurality of first indicator holes ( 12 ) equidistantly given on at least one of the side edge parts ( 1   a ), and a plurality of second indicator holes ( 13 ) given on at least one of the side edge parts ( 1   a ) on a straight line different from a row of the first indicator holes ( 12 ) at spacings shorter than spacings of the first indicator holes ( 12 ) are provided, and the second indicator holes ( 13 ) are each provided to a side of a trailing-end mark ( 11   b ), and each gradually comes closer to a leading-end mark ( 11   a ) as the long medium ( 1 ) runs toward a trailing end.

RELATED APPLICATION

This patent application is a continuation of co-pending U.S. patentapplication Ser. No. 13/700,105, filed on Apr. 2, 2013, and entitled“LONG MEDIUM,” which is hereby incorporated by reference.

FIELD OF THE INVENTION

This invention relates to a long medium provided with marks near a sideedge portion in a longitudinal direction for use in a printer, aplotter, or the like (hereinafter simply referred to as a printer or thelike) and, in more detail, a long medium wound, for example, in a rollshape, with which the remaining amount can be mechanically detected andalso visually recognized. The present application asserts priorityrights based on JP Patent Application 2011-068994 filed in Japan on Mar.25, 2011. The total contents of disclosure of the patent application ofthe senior filing date are to be incorporated by reference into thepresent application.

BACKGROUND OF THE INVENTION

A long medium having an adhesive sheet temporarily adhered to a releasesheet is provided with a plurality of holes in which a sprocket, atractor, or the like is engaged on a side edge part in a longitudinaldirection, and runs with the sprocket or tractor being engaged in theseholes to rotate. The long medium that is caused to run by using thesprocket or tractor does not diagonally run at the time of print output,compared with a scheme in which the long medium is interposed betweenrollers to be conveyed with a force of friction with the rollers, andthus the long medium can be caused to linearly run in a stable manner.Therefore, in a printer for outputting a long medium of several meters,for example, a long medium that is caused to run by using a sprocket ortractor without positional misalignment is used.

This long medium is used as a print medium on which figures andcharacters are to be printed indoors, outdoors, on a nameplate, or thelike. For example, in a printer using a thermal head as a head, a dye onan ink ribbon is transferred onto a print layer to form a predeterminedimage. Then, after printing, the long medium is cut out by aprinter-incorporated or separate cutting device into a predeterminedshape, the release sheet is peeled off, and is then affixed to apredetermined place.

The long medium of this type has a roll shape, is set at a printer orthe like, and is caused to run by a sprocket or tractor. When printingwith a length of several meters is performed, if the long medium runsout in the course of printing, the long medium printed so far goes towaste. To prevent this, in the printer or the like, the set roll-shapedlong medium is removed, and the roll diameter is visually checked.However, in visual checking, the remaining amount is visually estimated,and it is therefore difficult to correctly grasp the remaining amount.

Moreover, when the set roll-shaped long medium is removed and theremaining amount is visually checked, if the remaining amount issufficient, the roll-shaped long medium is required to be set again. Onthe other hand, if the remaining amount is insufficient, a newroll-shaped long medium is required to be set at the printer or thelike. The work of resetting the long medium requires a work of rewindingthe long medium drawn from the printer or the like into a roll, and thiswork is cumbersome.

Meanwhile, a long medium is desired that allows the remaining amount ofthe long medium set at a printer or the like to be visually checked atease.

For example, in Patent Document 1 discloses that indicators indicatingthe remaining amount are given to a long web. In Patent Document 1,specifically, first indicators are equidistantly given, secondindicators are given at second spacings different from spacing of thefirst indicators, and each spacing between adjacent ones of the firstindicators and a relevant one of the second indicators is changed alongthe length of the medium. However, when the length of the medium isdesired to be visually checked before the medium is set at the printeror the like, while the length is indicated by the spacing between theadjacent ones of the first indicators and the relevant second indicator,it is not possible to grasp a visually-specific remaining length. Forexample, when an output of three meters is desired to be obtained, it isdifficult to visually determine whether a medium has three meters orlonger left by using the first indicators and the second indicatorsshown on the medium to be set at a printer or the like.

Moreover, Patent Document 2 also discloses that indicators indicatingthe remaining amount are given to a long web. Specifically, this PatentDocument 2, discloses that multi-stage marks are provided on a longsheet and the remaining amount is shown with a pattern formed ofcombinations of the marks. When the remaining amount is shown with apattern formed of combinations of the marks, a method of giving apattern formed of combinations of black and white, that is, formed of abinary number, can achieve the highest resolution power.

However, when the remaining amount is displayed with a pattern of blackand white, if the remaining amount is tried to be visually grasped onlywith the sheet, the binary pattern is required to be decoded, and it isdifficult for general users to grasp the remaining amount.

PRIOR-ART DOCUMENTS Patent Documents

PTL 1: Japanese Patent No. 3756308

PTL 2: Japanese Patent Application Laid-Open No. 4-235853

SUMMARY OF THE INVENTION

The present invention was made in view of the problems as describedabove, and has an object of providing a long medium capable of visuallygrasping the remaining amount of the long medium at ease and in acorrect manner.

Also, another object of the present invention is to provide a longmedium allowing mark indicators to be achieved at low cost withoutnarrowing a print area even if the mark indicators are provided.

Furthermore, still another object of the present invention is to providea long medium allowing the remaining amount of the long medium to beeasily detected.

To solve the problems described above, a long medium according to thepresent invention is a long medium having an adhesive sheet temporarilyadhered to a release sheet, and includes a plurality of holesequidistantly provided on a straight line on both side edge parts in alongitudinal direction, a plurality of first indicators repeatedly givenon at least one of the side edge parts on a straight line at spacings ofan integral multiple of spacings of the plurality of holes, and aplurality of second indicators repeatedly given on at least one of theside edge parts on a straight line different from a row of the firstindicators at spacings shorter than spacings of the first indicators,wherein the plurality of holes, the plurality of first indicators, andthe plurality of second indicators are provided approximately inparallel to one another, a spacing between a leading-end hole and atrailing-end hole among the plurality of holes sectioned by adjacentones of the first indicators near inside the adjacent ones of the firstindicators indicates a reference length of the long medium, a firstratio of a spacing between the plurality of the holes and a unit lengthof the long medium and a second ratio of a difference between a spacingbetween the first indicators and a spacing between the second indicatorsand a change amount of a length of the long medium indicated by thisdifference are approximately equal to each other, the second indicatorsare provided to a side of the trailing-end hole, and each gradually comecloser to the leading-end hole that pairs up with the trailing-end holesas the long medium runs toward a trailing end, and a spacing between theleading-end hole and the second indicator is approximately proportionalto a remaining amount of the long medium. According to the long mediumof the present invention, since the spacing between the holes on theside edge art of the long medium is provided as a mark indicator eachindicating a unit length of the long medium, the remaining amount of thelong medium can be visually grasped at ease by comparing this hole and adistance from the first indicator to the second indicator. Furthermore,according to the long medium of the present invention, the firstindicators and the second indicators are mechanically detected bydetecting means such as an optical sensor to calculate each distancefrom the first indicator to the second indicator, the remaining amountof the long medium can also be mechanically detected at ease.

The spacing between the first indicators and the spacing between thesecond indicators may be set so as to have a relation in which the longmedium runs out when the second indicator reaches a position of theleading-end hole.

The first indicators and the second indicators may have a translucencyhigher than that of any other area of the long medium.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram of the structure of a printer in which a longmedium to which the present invention is applied is used.

FIG. 2 is a longitudinal sectional view of the long medium to which thepresent invention is applied.

FIG. 3 is a plan view of the long medium to which the present inventionis applied.

FIG. 4 is a plan view of part of the long medium to which the presentinvention is applied.

FIG. 5 is a plan view of part of the long medium to which the presentinvention is applied.

FIG. 6 is a plan view of part of the long medium to which the presentinvention is applied.

FIG. 7 is a flowchart when a process of detecting the remaining amountthe long medium to which the present invention is applied.

FIG. 8 is a flowchart when a process of detecting a conveyance error ofthe long medium to which the present invention is applied.

FIG. 9 is a plan view of a first modification example of the long mediumto which the present invention is applied.

FIG. 10 is a block diagram of the structure of a cutting device in whichthe long medium to which the present invention is applied is used.

FIG. 11 is a plan view of a second modification example of the longmedium to which the present invention is applied.

FIG. 12 is a plan view of a third modification example of the longmedium to which the present invention is applied.

FIG. 13 is a plan view of a fourth modification example of the longmedium to which the present invention is applied.

FIG. 14 is a plan view of a fifth modification example of the longmedium to which the present invention is applied.

FIG. 15 is a plan view of a sixth modification example of the longmedium to which the present invention is applied.

FIG. 16 is a plan view of a first reference example of the long mediumto which the present invention is applied.

FIG. 17 is a plan view of a second reference example of the long mediumto which the present invention is applied.

DETAILED DESCRIPTION OF THE INVENTION

The long medium to which the present invention is applied is describedin detail below with reference to the drawings. Note that thedescription is made in the following order.

1. General outline of the long medium2. Description of the printer3. Description of the operation of the remaining amount detectingprocess by the printer4. Description of the operation of the conveyance error detectingprocess by the printer5. Modification examples6. First reference example7. Second reference example

1. General Outline of the Long Medium

As depicted in FIG. 1, a long medium 1 to which the present invention isapplied is, for example, used at a printer 2 in which a thermal head isused as a printer head. In this printer 2, for example, figures andcharacters are to be printed indoors, outdoors, on a nameplate, or thelike, and an image having a length of several meters is printed in thecase of a long image.

Also, in this long medium 1, as depicted in FIG. 2, an adhesive sheet 3having a front surface 3 a as a print layer and a back surface 3 b withan adhesive layer 4 formed thereon is temporarily adhered to a frontsurface 5 a of a release sheet 5 via an adhesion layer 4. This adhesivesheet 3 is provided so as to be narrower than the release sheet 5.Therefore, both of side edge parts 1 a of the long medium 1 in alongitudinal direction are non-print areas where the adhesive sheet 3 asa print layer is not provided. Furthermore, on an entire back surface 5b side of the release sheet 5, a design such as a grid, a logoindicating a product name, or the like has already been printed. Notethat a logo or the like may not be printed on the back surface 5 b sideof the release sheet 5.

As depicted in FIG. 3, the long medium 1 is given a mark part 10allowing the remaining amount of the long medium 1 to be visually andmechanically grasped. This mark part 10 has mark holes 11 serving asmark indicators, first indicator holes 12 serving as first indicatorsindicating a reference position when the remaining amount of the longmedium 1 is displayed, and second indicator holes 13 serving as secondindicators each to which a distance from a relevant first indicatorindicates the current remaining amount of the long medium 1.

Specifically, the mark holes 11 are equidistantly provided toward thelongitudinal direction on both of the side edge parts 1 a of the longmedium 1 in the longitudinal direction, that is, on both of side edgeparts of the release sheet 5 where the adhesive sheet 3 is not provided(on the non-print areas). The first indicator holes 12 are repeatedlyand equidistantly given toward the longitudinal direction on one of theside edge parts 1 a in the longitudinal direction. The second indicatorholes 13 are repeatedly and equidistantly given on one of the side edgeparts 1 a in the longitudinal direction that is the same side as that ofthe first indicator holes 12.

These mark holes 11, first indicator holes 12, and second indicatorholes 13 are provided so as to be approximately parallel to each other.The mark holes 11 are provided on a straight line L1 toward thelongitudinal direction. The first indicator holes 12 are providedbetween the mark holes 11, 11 on the same straight line L1 as that ofthe mark holes 11. Note that, as will be described further below, thefirst indicator holes 12 may be provided on a straight line differentfrom that of the mark holes 11. The second indicator holes 13 areprovided on a straight line L2 different from a row of the firstindicator holes 12, for example, inside the row of the first indicatorholes 12 in a width direction.

Furthermore, the mark holes 11, the first indicator holes 12, and thesecond indicator holes 13 are through holes penetrating through the longmedium 1. For example, the mark holes 11 are each formed in a circularshape, and the first indicator holes 12 and the second indicator holes13 are each formed in a long hole shape. Still further, the mark holes11 are, for example, sprocket holes, in which projections 20 a of asprocket 20 of the printer 2, which will be described further below, areengaged. With the projections 20 a of the sprocket 20 engaged in themark holes 11, when the sprocket 20 is driven and rotated, the longmedium 1 is conveyed in the longitudinal direction.

Still further, the first indicator holes 12 and the second indicatorholes 13 each have a hole diameter provided so as to be smaller thanthat of each mark hole 11. Therefore, having shapes and sizes differentfrom those of the mark holes 11, the first indicator holes 12 and thesecond indicator holes 13 can be easily discriminated from the firstholes 11.

Still further, the first indicator holes 12 are repeatedly given over anoverall length L of the long medium 1 from a tip 1 b to a trailing end 1c with a spacing P1, which is an integral multiple nd (n is an integer)of a spacing d between the plurality of mark holes 11. The secondindicator holes 13 are repeatedly given from a position shifted by apredetermined distance from the tip 1 b of the long medium 1 in thelongitudinal direction to a trailing end 1 c side with a spacing P2shorter than that of the first indicator holes 12.

Note that the first indicators 12 are indicators for equidistantlysectioning the mark holes 11 and the first indicators 12 are notnecessarily required to be equidistantly, successively, and repeatedlygiven with the spacing. Spacings of two or more types may be alternatelyand repeatedly given.

The first indicators 12 can be provided at any positions as long as theycan be grasped as being on the same straight line as that of the markholes 11, and the second indicators 13 can be provided at any positionsas long as they can be grasped as being on a straight line differentfrom that of the mark holes 11. For example, a shape may be placed suchthat part of the indicators projects on two different straight lines ofthe mark hole 11 and the second indicators 13.

Furthermore, the plurality of mark holes 11 each interposed betweenadjacent first indicator holes 12, 12 to be sectioned are mark holes asa reference when the remaining amount of the long medium 1 is grasped,and the spacing d of adjacent mark holes 11 indicates a unit length M ofthe long medium 1. Here, a mark hole 11 near the inside of the firstindicator hole 12 at a tip 1 b side of the long medium 1 serves as aleading-end mark hole 11 a, and a mark hole 11 near the inside of thefirst indicator hole 12 at a trailing end 1 c side serves as atrailing-end mark hole 11 b that pairs up with the leading-end mark hole11 a. A distance between the paired leading-end mark hole 11 a andtrailing-end mark hole 11 b indicates a reference length of the longmedium 1, serving as a mark indicator. By contrast, the first indicatorholes 12 each indicate a boundary of mark indicators in a predeterminedsection.

Still further, the plurality of the mark holes 11, the plurality offirst indicator holes 12, and the plurality of second indicator holes 13are provided so that a first ratio between the spacing d between theplurality of mark holes 11 and the unit length M of the long medium 1and the second ratio between a difference between the spacing P1 betweenthe first indicator holes 12 and the spacing P2 between the secondindicators 13 and a change amount of the length of the long medium 1indicated by this difference are approximately equal to each other.

That is, a second indicator hole 13 that comes first and is closest tothe tip 1 b side of the long medium 1 indicates that the long medium 1is in a not-used state, and is therefore given so as to match atrailing-end mark hole 11 b that comes first and is given closest to thetip 1 b of the long medium 1. Then, a second indicator hole 13 thatcomes second and thereafter are given so that the second indicator hole13 gradually comes closer to the leading-end mark hole 11 a by apredetermined length along the length of the long medium as the longmedium 1 runs toward the trailing end 1 c. In other words, the secondindicator hole 13 that comes second is provided so that a spacing Hbetween the leading-end mark hole 11 a and the second indicator hole 13is gradually narrower by a predetermined length along the length of thelong medium 1 as the long medium 1 runs toward the trailing end 1 c.

Next, the spacing P1 between the first indicator holes 12 and thespacing P2 between the second indicator holes 13 are described by usingspecific values.

Here, as depicted in FIG. 4 to FIG. 7, for example, the case isdescribed in which the overall length L of the long medium 1 is set as15 m (15000 mm), the spacing d between the mark holes 11 is set as 10mm, and the unit length M of the long medium 1 indicated by this spacingd between the mark holes 11 is set as 1 m (1000 mm). In this case, afirst ratio S between the spacing d between the mark holes 11 and theunit length M of the long medium 1 is S=d/M=10/1000=1/100. That is, themark indicators formed of the plurality of mark holes 11 are displayedwith a 1/100 scale of the length of the long medium 1.

Furthermore, as the spacing P1 between the first indicator holes 12,P1≧L×S=15000×1/100=150 mm or longer is required to ensure markindicators for the overall length L of the long medium 1. Therefore,since the spacing P1 between the first indicator holes 12 is provided asa spacing of an integer multiple nd of the spacing d between mark holes11 as described above, from P1≧n×d, n>15 is required to be satisfied.

Here, each spacing between display sections is taken as a 1/d pitch, andn=16. With this, the spacing P1 between the first indicator holes 12 isP1=160 mm from P1=n×d. That is, the first indicator holes 12 are givenwith the pitch of 160 mm so that sixteen mark holes 11 are interposedeach between adjacent first indicator holes 12, 12.

And, as described above, since the first indicator holes 12 are givenwith the pitch of 160 mm, the length of the long medium 1 is shorter by160 mm from the tip 1 b toward the trailing end 1 c of the long medium1. Therefore, from the tip 1 b to the trailing end 1 c of the longmedium 1, the second indicator holes 13 are given so as to each comecloser by an amount obtained by multiplying 160 mm by the first ratio Sdescribed above, that is, 1/100, to the leading-end mark hole 11 arather than the adjacent second indicator hole 13 on the tip 1 b side.That is, the spacing P2 between the second indicator holes 13 isP2=P1(1−S). Thus, the spacing P2 between the second indicator holes 13is P2=160×(1−(1/100))=158.4 mm.

Therefore, as depicted in FIG. 4, at the tip 1 b of the long medium 1,the second indicator hole 13 is placed so as to match the trailing-endmark hole 11 b that comes first and is given closest to the tip 1 b ofthe long medium 1. The trailing-end mark hole 11 b matching this secondindicator hole 13 is a mark hole 11 that comes fifteenth from theleading-end mark hole 11 a that pairs with the trailing-end mark hole 11b on the trailing end 1 c side. Therefore, it is possible to visuallygrasp that the long medium 1 has the remaining amount of approximately15 m.

Furthermore, as depicted in FIG. 5, at a position approximately 5 m fromthe tip 1 b of the long medium 1, the second indicator hole 13 is placedso as to approximately match a mark hole 11 that comes tenth from theleading-end mark hole 11 a on the trailing end 1 c side. With this, itis possible to visually grasp that the long medium 1 has the remainingamount of approximately 10 m. Still further, as depicted in FIG. 6, at aposition approximately 15 m from the tip 1 b of the long medium 1, thesecond indicator hole 13 is placed so as to approximately match theleading-end mark hole 11 a. With this, it is possible to visually graspthat the long medium 1 has no remaining amount.

Therefore, since the long medium 1 to which the present invention isapplied is provided with the spacing d between the mark holes 11 on theside edge part 1 a as mark indicators each indicating the unit length Mof the long medium 1, the remaining amount of the long medium 1 can bevisually grasped at ease and in a correct manner by comparing the markholes 11 and the distance from the leading-end mark hole 11 a to thesecond indicator hole 13.

Furthermore, in the long medium 1 to which the present invention isapplied, with the holes 11, which are sprocket holes providedconventionally for conveyance, being taken as mark indicators, noseparate mark indicators are not required to be provided, and markindicators can be provided at low cost, thereby inhibiting an increasein cost of the long medium 1. Still further, in the long medium 1 towhich the present invention is applied, the print area is not narrowedeven mark indicators are provided, and the print area can be widelyprovided. Still further, in the long medium 1, indicators are notrequired to be forcibly provided on the front surface 5 a of the releasesheet 5 where ink is less prone to be fixed ink is less prone to befixed on the back surface 5 b of the release sheet 5 where print hasalready been present.

2. Description of the Printer

The long medium 1 as described above is mounted on the printer 2 asbeing wound like a roll paper sheet as depicted in FIG. 1. Specifically,in the printer 2, the roll of the long medium 1 is rotatablyaccommodated in an accommodating unit (not shown) inside a device mainbody. The long medium 1 drawn from the roll is caused to run with thesprocket 20 being engaged in the mark holes 11 on both of the side edgeparts 1 a and being guided by a plurality of guide pins (not shown) andguide rollers (not shown). Furthermore, in the printer 2, a thermal head21 for applying heat energy according to print data is placed so as toface a platen 22 on an upstream side of the sprocket 20 in a runningdirection of the long medium 1. Still further, in the printer 2, an inkribbon cartridge 23 is inserted, and an ink ribbon 24 is interposedbetween the thermal head 21 and the platen 22. The ink ribbon 24 issuperposed between the thermal head 21 and the platen 22, and the inkribbon 24 is brought into contact with the print layer of the longmedium 1 in a pressed manner. In the long medium 1, with heat energybeing applied by the thermal head 21 according to the print data, a dyeof the ink ribbon 24 is transferred to the print layer of the longmedium 1, thereby forming an image.

Furthermore, a cutting mechanism 25 for cutting the printed long medium1 is provided on a downstream side of the sprocket 20. The cuttingmechanism 25 includes a cutter 25 a moving in a width direction of thelong medium 1. With the cutter 25 a moving in the width direction of thelong medium 1 and the long medium 1 running, the long medium 1 is cutout into a predetermined shape.

Also, a remaining amount detection sensor 26 is provided on an upstreamside of the thermal head 21 or on a downstream side of the cuttingmechanism 25. The remaining amount detection sensor 26 has a firstlight-emitting unit 26 a detecting the first indictor holes 12 and afirst light-receiving unit 26 b detecting light emitted from the firstlight-emitting unit 26 a placed so as to face each other, and has asecond light-emitting unit 26 c detecting the second indictor holes 13and a second light-receiving unit 26 d detecting light emitted from thesecond light-emitting unit 26 c placed so as to face each other.

The printer 2 uses a control unit 27 such as a microcomputer to controla motor driving the sprocket 20, the remaining amount detection sensor26, the cutting mechanism 25, the thermal head 21, and others. Forexample, the control unit 27 calculates the remaining amount of the longmedium 1 based on a phase difference between outputs from the first andsecond light-receiving units 26 b and 26 d of the remaining amountdetection sensor 26. Furthermore, the control unit 27 causes a user tobe notified through a display unit or a loudspeaker of a shortage of thelong medium 1 when the remaining amount of the long medium 1 is shorterthan the length of the print area according to print data.

Note that the printer 2 is not restricted to include the thermal head21, and can be any as long as printing is made on the long medium 1. Forexample, the printer 2 may be a printer including a head of an ink jettype in which ink is pressed by pressure generated from a heater or apiezo element and the pressed ink is discharged from a discharge port asdroplets to the long medium 1 to print an image or character on the longmedium 1. Also, the ink ribbon may be of a single color, or dyes ofyellow, cyan, magenta, black, and others may be panel-sequentiallyprovided on one ribbon.

3. Description of the Operation of the Remaining Amount DetectingProcess by the Printer

Next, the operation of a remaining amount detecting process by theabove-configured printer 2 is described with reference to a flowchart ofFIG. 7. Here, for example, as depicted in FIG. 5, the case is describedin which the remaining amount of the long medium 1 having apredetermined length from the tip 1 b already used is detected. Notethat a two-dot chain line in FIG. 5 indicates a midcourse tip 1 e.

At step S1, when the long medium 1 is mounted on the printer 2 or atpower-on or the like with the long medium 1 being mounted on the printer2, the control unit 27 performs an initializing process. Specifically,the control unit 27 resets a count of a conveyance distance of the longmedium 1 to be counted up according to the rotation amount of the motordriving the sprocket 20. Furthermore, the control unit 27 resets a countof hole diameters of the first indicator holes 12 and the secondindicator holes 13.

At step S2, the control unit 27 causes the long medium 1 to be conveyed.Specifically, the control unit 27 causes the long medium 1 drawn fromthe roll to run by causing the motor to drive the sprocket 20 engaged inthe mark holes 11 on both of the side edge parts 1 a and causing theplurality of guide pins and guide rollers to guide. Furthermore, thecontrol unit 27 counts up a conveyance distance of the long medium 1.

At step S3, the control unit 27 causes the remaining amount detectionsensor 26 to start a process of detecting the first indicator holes 12and the second indicator holes 13 of the long medium 1 being conveyed.

At step S4, the control unit 27 causes the first light-emitting unit 26a and the first light-receiving unit 26 b to detect a first indicatorhole 12 closest to the midcourse tip 1 e. Here, the control unit 27causes a conveyance distance and a hole diameter of the first indicatorhole 12 to be detected. Note that the hole diameter mentioned herein isa diameter when the first indicator holes 12 and the second indicatorholes 13 each have a circular shape and is a length in the longitudinaldirection when they each have a long hole shape. Then, this holediameter is calculated based on the phase of outputs from the first andsecond light-receiving units 26 b and 26 d.

Furthermore, after the first indicator hole 12 closest to the midcoursetip 1 e is detected, the control unit 27 causes the secondlight-emitting unit 26 c and the second light-receiving unit 26 d todetect a second indicator hole 13 on the trailing end 1 c side from thedetected first indicator hole 12. Here, the control unit 27 causes aconveyance distance and a hole diameter of the second indicator hole 13to be detected. Then, at step S5, the control unit 27 ends detection ofthe first indicator hole 12 and the second indicator hole 13. Note thatwhen the first indicator hole 12 and the second indicator hole 13 cannotbe detected for a predetermined time and with conveyance by apredetermined distance, the control unit 27 may stop the operation andcause the user to be notified via the display unit or the loudspeakerthat an authorized long medium 1 should be used.

At step S6, the control unit 27 calculates positions of the detectedfirst indicator hole 12 and second indicator hole 13. Specifically, thecontrol unit 27 subtracts a half length of the hole diameter of thefirst indicator hole 12 from the detected conveyance distance of thefirst indicator hole 12 to calculate a conveyance distance at a centerposition of the first indicator hole 12. Furthermore, the control unit27 subtracts a half length of the hole diameter of the second indicatorhole 13 from the detected conveyance distance of the second indicatorhole 13 to calculate a conveyance distance at a center position of thesecond indicator hole 13. Then, at step S7, the control unit 27 ends theprocess of calculating the conveyance distances at the center positionsof the first indicator hole 12 and the second indicator hole 13.

At step S8, the control unit 27 subtracts the conveyance distance at thecenter position of a first indicator hole 12 that comes first from themidcourse tip 1 e from the conveyance distance at the center position ofa second indicator hole 13 that comes first to calculate a first spacingbetween the first indicator hole 12 that comes first and the secondindicator hole 13 that comes first.

Then, the control unit 27 detects the remaining amount of the longmedium 1 from the first spacing H. Specifically, the mark indicators andthe length of the long medium 1 have a relation of the first ratio S.For example, the mark indicators are displayed with a 1/100 scale of thelength of the long medium 1. Therefore, the remaining amount of the longmedium 1 can be calculated with the first spacing H and the first ratioS. For example, the remaining amount of the long medium 1 can becalculated by multiplying the first spacing H by 100. As such, theprinter 2 detects the remaining amount of the long medium 1.

Note that, thereafter, the control unit 27 compares the detectedremaining amount of the long medium 1 and the length of the print areaaccording to input print data. Then, when the detected remaining amountis shorter than the length of the print area, the control unit 27 stopsthe operation, and notifies the user via the display unit or theloudspeaker that the remaining amount is insufficient. Also, when thedetected remaining amount is longer than the print area, the controlunit 27 causes the long medium 1 to be rewounded and then conveyed againto cause printing according to the print data by using the ink ribbon24, the thermal head 21, and the platen 22, and then causes the cutter25 a to cut out according to cut-out data. Furthermore, even at the timeof printing, the operations from step S3 to step S8 are performed toalways detect the remaining amount of the long medium 1.

That is, in the long medium 1 to which the present invention is applied,since the first indicator holes 12 and the second indicator holes 13 arethrough holes, by only providing an optical sensor capable of detectinga through hole to the printer 2, the first indicator hole 12 and thesecond indicator hole 13 can be easily detected. Therefore, in the longmedium 1 to which the present invention is applied, the remaining amountof the long medium 1 can also be mechanically detected at ease.

4. Description of the Operation of the Conveyance Error DetectingProcess by the Printer

Next, the operation of a conveyance error detecting process by theprinter 2 is described with reference to a flowchart of FIG. 8. Here, aswith the operation of the remaining amount detecting process, forexample, the case of the long medium 1 having a predetermined lengthfrom the tip 1 b already used is described.

At step S10, for example, when the long medium 1 is conveyed at the timeof printing or the like, the control unit 27 performs operations similarto the operations of the remaining amount detecting process at step S1to step S8 described above, thereby performing a remaining amountdetecting process. While one first indicator hole 12 and one secondindicator hole 13 are detected to detect the remaining amount of thelong medium 1 closest to the midcourse tip 1 e in the operations of theremaining amount detecting process described above, the control unit 27causes a plurality of first indicator holes 12 and second indicatorholes 13 to be detected to detect the remaining amounts at the pluralityof points at step S10. For example, the control unit 27 causes theremaining amounts at three points.

At step S11, the control unit 27 calculates a first change amountbetween a first remaining amount and a second remaining amount and asecond change amount between the second remaining amount and a thirdremaining amount.

At step S12, the control unit 27 determines whether the first changeamount and the second change amount are within certain or prescribedamounts. Then, when the control unit 27 determines that the first changeamount and the second change amount are not the certain or withinprescribed amounts, the procedure goes to step S14, stopping theoperation and causing the user to be notified via the display unit orthe loudspeaker of a conveyance anomaly. Note that the control unit 27may cause notification of a conveyance anomaly and also may cause theuser to be notified that an authorized long medium 1 should be used.Also, when the control unit 27 determines that the first change amountand the second change amount are within the certain or prescribedamounts, the procedure goes to step S13, continuing the conveyance andending the conveyance, for example, after the end of a printing process.As such, the printer 2 detects a conveyance error of the long medium 1.

Therefore, in the long medium 1 to which the present invention isapplied, at the conveyance by the printer 2, a jam of the long medium 1can be detected by detecting the change amount of the remaining amountof the long medium 1. Thus, in the long medium 1 to which the presentinvention is applied, a conveyance anomaly of the long medium 1 can behandled, such as stopping the printing operation.

5. Modification Examples

Note that the long medium 1 is not restricted to a roll paper sheetwound in a roll shape, and may be a fan-fold paper sheet alternatelyfolded along perforation.

Furthermore, the long medium 1 is not restricted to the one having theadhesive sheet 3 provided so as to be narrower than the release sheet 5.For example, in the long medium 1, the adhesive sheet 3 may be providedso as to have approximately the same width as that of the release sheet5, the adhesive sheet 3 may be provided on the entire surface of therelease sheet 5, and the mark holes 11, the first indicator holes 12,and the second indicator holes 13 may be provided on a side edge part ofthe adhesive sheet 3.

Still further, the mark holes 11, the first indicator holes 12, and thesecond indicator holes 13 are not restricted to be provided so as tohave the shapes, sizes, and spacing described above. The mark holes 11each may have any shape, size, and spacing as long as the shape, size,and spacing allow the projections 20 a of the sprocket 20 of the printer2 to be engaged in the mark holes 11. Furthermore, the first indicatorholes 12 and the second indicator holes 13 each may be formed in acircular shape or a rectangular shape other than a long hole shape, andmay have the same shape and size as those of the mark holes 11. Stillfurther, the first indicator holes 12 and the second indicator holes 13may have different shape and sizes.

Still further, the first indicator holes 12 and the second indicatorholes 13 are not restricted to be given on only one of the side edgeparts 1 a, and may be given on both. In this case, by giving the firstindicator holes 12 and the second indicator holes 13 at the sameposition on both of the side edge parts 1 a in the longitudinaldirection, these holes can also be used as indicators for identifyingthe mark holes 11 at the same position in the longitudinal directionwhen the long medium 1 is set with the long medium 1 being coupled tothe projections 20 a of the sprockets 20. Thus, the mark holes 11 can beprevented from being diagonally set due to a step deviation.

Still further, the first indicator holes 12 and the second indicatorholes 13 are not restricted to be given up to a position where theremaining amount of the long medium 1 is approximately 0 m, and may begiven to a position where the remaining amount of the long medium 1 hasa predetermined length, for example, 1 m, left. Still further, the firstindicator holes 12 and the second indicator holes 13 are not restrictedto be given from the tip 1 b of the long medium 1, and may be given froma predetermined position, for example, a position at 10 m, from the tip1 b of the long medium 1 to the trailing end 1 c side. Still further,the first indicator holes 12 and the second indicator holes 13 may begiven from a predetermined position to a position where the remainingamount of the long medium 1 has a predetermined length left, from thetip 1 b of the long medium 1 to the trailing end 1 c side.

Still further, as depicted in FIG. 9, the long medium 1 may be providedwith reference marks 14 each indicating a boundary of the markindicators by the mark holes 11. These reference marks 14 are throughholes provided on a same straight line L2 as the second indicator holes13 so as to match the first indicator holes 12. In the long medium 1,with the reference marks 14 provided on the same straight line L2 as thesecond indicator holes 13 so as to match the first indicator holes 12,the boundary of the mark indicators can be easily grasped. Stillfurther, when the spacing between the first indicator hole 12 and thesecond indicator hole 13 is read, the reference marks 14 serve as asubstitute for the first indicator holes 12, and the spacing between thefirst indicator hole 12 and the second indicator hole 13 can be easilygrasped.

Still further, the long medium 1 is not restricted to be used in theprinter 2. As depicted in FIG. 10, the long medium 1 to which thepresent invention is applied can be used in a cutting device 30 forcutting the long medium 1 printed on a printer not including the cuttingmechanism 25. This cutting device 30 has a structure approximatelysimilar to the structure with the thermal head 21 removed from theprinter 2, and therefore details are omitted.

Still further, in the long medium 1, the unit length M may be setaccording to the length of the long medium 1. For example, the unitlength M may be set long according to the length of the long medium 1 isincreased. With this, the length in a certain section from theleading-end mark hole 11 a to the trailing-end mark hole 11 b can bekept without changing the spacing between the mark holes 11. For thisreason, the mark indicators can be placed without excessively increasingthe length of the certain section from the leading-end mark hole 11 a tothe trailing-end mark hole 11 b, an amount of the long medium 1 to bedrawn can be decreased when the remaining amount of the long medium 1 isvisually checked, thereby making a visual check easier.

Still further, as depicted in FIG. 11, in the long medium 1, the markhole 11 that comes first from the tip 1 b side is set as the leading-endmark hole 11 a from among the plurality of mark holes 11 interposedbetween the first indicator holes 12, 12 to be sectioned and the markhole 11 that comes sixteenth is set as the trailing-end mark hole 11 b.However, for example, the position of the trailing-end mark hole 11 bmay be set at a mark hole 11 that comes eleventh from the tip 1 b side,according to the overall length of the long medium 1. In this case, thetrailing-end mark hole 11 b that matches a relevant second indicatorhole 13 is a mark hole 11 that comes tenth from the leading-end markhole 11 a that pairs up to the trailing end 1 c side, and it istherefore possible to visually grasp that the long medium 1 has theremaining amount of approximately 10 m.

Still further, as depicted in FIG. 12, in the long medium 1, thepositions of the leading-end mark hole 11 a and the trailing-end markhole 11 b may be set in an offset manner. For example, a mark hole 11that comes sixth from the first mark hole 12 on the tip 1 b side of thelong medium 1 from among the mark holes 11 may be set as the leading-endmark hole 11 a. Here, the relevant second hole 13 is also offsetaccording to the leading-end mark hole 11 a and if it is placed so thatthe second indicator hole 13 approximately matches the leading-end markhole 11 a when the remaining amount of the long medium 1 runs out, it ispossible to visually grasp that the remaining amount has run out. Here,by placing the trailing-end mark hole 11 b in an offset manner near thefirst indicator 12 on the tip 1 b side and comparing the distance of thedistance from the first indicator hole 12 on the tip 1 b side to thesecond indicator hole 13, it is possible to visually grasp by how longmeters the long medium 1 has been used, instead of the remaining amountof the long medium 1.

Still further, as depicted in FIG. 13, in the long medium 1, theleading-end mark hole 11 a and the trailing-end mark hole 11 b may beplaced in an offset manner to the trailing end side 1 b of the longmedium 1. For example, the leading-end mark hole 11 a is offset so as tomatch a mark hole 11 that comes fourth from the first indicator hole 12on the tip side of the long medium 1, and the trailing-end hole 11 b isoffset so as to match a mark hole 11 that comes fourteenth. With this,since the first indicator holes 12 and the second indicator holes 13 aregiven at different steps in processing of the long medium 1, offsettingthe positions of the leading-end mark hole 11 a and the trailing-endmark hole 11 b may be easier for processing. When these positions areoffset, the user is notified that the leading-end mark hole 11 a and thetrailing-end mark hole 11 b are placed in an offset manner from thefirst indicators 12 by using a known method such as describing as suchon a package or an instruction manual. With this, the user can visuallygrasp the remaining amount of the long medium 1.

Still further, as depicted in FIG. 14, in the long medium 1, a film 15may be affixed onto each first indicator 12 and each second indicator13. Specifically, the film 15 is affixed so as to cover the through holeof the first indicator 12 and the through hole of the second indicator13. With this, an area of the first indicator 12 and the secondindicator 13 where the film 15 is affixed has a translucency higher thanthat of any other area of the long medium 1. Therefore, in the longmedium 1, it is possible to detect the first indicator 12 and the secondindicator 13 with the remaining amount detection sensor 26 morecorrectly than the case of the first indicator 12 and the secondindicator 13 formed of simple through holes. Furthermore, with the film15 having a color different from those of the surroundings, the firstindicator 12 and the second indicator 13 can also be visuallydistinguished at ease.

Still further, as depicted in FIG. 15, in the long medium 1, the firstindicator 12 and the second indicator 13 are not restricted to bethrough holes, and may be provided as a translucent part 16 thinner thanany other area of the long medium 1 or formed of a mesh so as to have atranslucency higher than that of any other area of the long medium 1.With this, in the long medium 1, the first indicator 12 and the secondindicator 13 can be detected by the remaining amount detection sensor 26more correctly than the case of the first indicator 12 and the secondindicator 13 formed of simple through holes. Since the translucent part16 that is thin or formed of a mesh is also visually and tactuallydifferent from the surroundings, the first indicator 12 and the secondindicator 13 can be distinguished at ease.

6. First Reference Example

Next, a long medium 40 is described, which is a first reference exampleof the long medium 1 to which the present application is applied.

As depicted in FIG. 16, the long medium 40 of the first referenceexample has mark holes, which are through holes different from sprocketholes, while the mark holes 11 are sprocket holes in the long medium 1described above. Mark holes 41 of the long medium 40 have the samestructure as that of the mark holes 11 of the long medium 1 except thatthe mark holes 41 are equidistantly provided on a straight line along alongitudinal direction on one of side edge parts 40 a of the long medium40 in the longitudinal direction. Furthermore, first indicators 42 ofthe long medium 40 have the same structure as that of the firstindicator holes 12 of the long medium 1 except that the first indicators42 are given on a straight line inside a row of the mark holes 41 on oneof the side edge parts 40 a and the same side of the mark holes 41.Still further, second indicators 43 of the long medium 40 have the samestructure as that of the second indicator holes 13 of the long medium 1.Still further, in the long medium 40, a plurality of sprocket holes 44are equidistantly provided on a straight line outside the row of themark holes 41 on both of the side edge parts 40 a, 40 a. These markholes 41, first indicators 42, second indicators 43, and sprocket holes44 are provided on a side edge part of a release sheet 5 not providedwith an adhesive sheet 3 as a print layer.

In the long medium 40 of the first reference example described above,the mark holes 41 are required to be separately provided, and the printarea is narrower than that of the long medium 1 described above.However, as with the long medium 1 described above, the remaining amountcan be visually grasped at ease and in a correct manner by comparing themarks holes 41 and the distance from the leading-end mark hole 41 a orthe first indicator 42 to the second indicator 43.

Furthermore, in the long medium 40 of the first reference example, aswith the long medium 1 described above, the first indicator holes 42 andthe second indicator holes 43 are through holes. Thus, by only providingan optical sensor capable of detecting a through hole to the printer 2,the first indicator hole 42 and the second indicator hole 43 can beeasily detected, and the remaining amount of the long medium 40 can alsobe mechanically detected at ease.

Note that the long medium 40 may be provided with the adhesive sheet 3as a print layer on the entire surface of the release sheet 5. In thiscase, the mark holes 41, the first indicators 42, the second indicators43, and the sprocket holes 44 are provided on the side edge part 40 a ofthe long medium 40, that is, a side edge part of the adhesive sheet 3.

Furthermore, the long medium 40 may be conveyed in a longitudinaldirection by being interposed by rollers. In this case, the long medium40 is not required to be provided with the sprocket holes 44, and themark holes 41 are required to be provided separately. However, as withthe long medium 1 described above, the remaining amount can be visuallyand mechanically grasped at ease and in a correct manner withoutnarrowing a print area.

7. Second Reference Example

Next, a long medium 50 is described, which is a second reference exampleof the long medium 1 to which the present invention is applied.

As depicted in FIG. 17, in the long medium 50 of the second referenceexample, in contrast to the first reference example described above inwhich the mark holes 41, the first indicators 42, and the secondindicators 43 of the long medium 40 are through holes, these indicatorsare printed. Specifically, the long medium 50 is provided with anadhesive sheet 3 as a print layer on an entire surface of a releasesheet 5, and marks 51 corresponding to the mark holes 41, firstindicators 52 corresponding to the first indicators 42, and secondindicators 53 corresponding to the second indicators 43 are printed on aside edge part of a front surface 3 a of the adhesive sheet 3 or on aside edge part of a back surface 5 b of the release sheet 5. The marks51 each indicate, for example, a mark line 51 c or a remaining amountnumerical value 51 d corresponding to the mark line 51 c. The firstindicators 52 and the second indicators 53 are, for example,rectangular-shaped, circular-shaped, or long-hole-shaped marks.Furthermore, the long medium 50 is conveyed in a longitudinal directionas being interposed between rollers of a printer 2 or a cutting device30.

The long medium 50 of the second reference example as described abovehas a print area narrower than that of the long medium 1 described abovewhen the first indicators 52 and the second indicators 53 are printed onthe side edge part of the front surface 3 a of the adhesive sheet 3.When they are printed on the back surface 5 b of the release sheet 5,although printing is difficult, the remaining amount can be visuallygrasped at ease and in a correct manner by comparing the marks 51 andthe distance from the start-end mark 51 a or the first indicator 52 tothe second indicator 53, as with the long medium 1 described above.

Furthermore, the long medium 50 of the second reference example asdescribed above, since the first indicators 52 and the second indicators53 are printed marks, as with the long medium 1 described above, by onlyproviding an optical sensor capable of detecting a printed mark to theprinter 2 in place of an optical sensor capable of detecting a throughhole, the first indicator 52 and the second indicator 53 can be easilydetected, and the remaining amount of the long medium 50 can also bemechanically detected at ease.

Note that sprocket holes may be provided outside a row of the marks 51and, the long medium 50 may be conveyed by a sprocket 20 of the printer2 or the cutting device 30 in the longitudinal direction. Furthermore,in the long medium 50, the adhesive sheet 3 as a print layer may beprovided so as to be narrower than the release sheet 5 and the markholes 51, the first indicators 52, and the second indicators 53 may beprinted on the side edge part of the front surface 5 a or the backsurface 5 b of the release sheet 5.

1-9. (canceled)
 10. An image forming apparatus for outputting to a long medium having an adhesive sheet having a first adhesive side edge part and a second adhesive side edge part, the adhesive sheet temporarily adhered to a release sheet having a first release side edge part and a second release side edge part, the long medium comprising: a plurality of holes equidistantly provided on a straight line on both the first side edge part and the second side edge part in a longitudinal direction of the release sheet or all of the first adhesive side edge part and the second adhesive side edge part of the adhesive sheet and the first release side edge part and the second release side edge part of the release sheet; a plurality of first indicators repeatedly given on at least one of the first or second release side edge parts of the release sheet or all of the first adhesive side edge part and the second adhesive side edge part of the adhesive sheet and the first release side edge part and the second release side edge part of the release sheet on a straight line at spacings of an integral multiple of spacings of the plurality of holes; and a plurality of second indicators for equidistantly sectioning the plurality of holes, the plurality of second indicators are repeatedly given on at least one of the first or second release side edge parts of the release sheet or all of the first adhesive side edge part and the second adhesive side edge part of the adhesive sheet and the first release side edge part and the second release side edge part of the release sheet on a straight line different from a row of the first indicators at spacings shorter than spacings of the first indicators, wherein the plurality of holes, the plurality of first indicators, and the plurality of second indicators are provided approximately in parallel to one another, a spacing between a leading-end hole and a trailing-end hole between the pair of first indicators indicates a reference length of the long medium, the leading-end hole of the plurality of holes sectioned by the adjacent first indicators are placed on a tip side of the long medium and the trailing-end hole of the plurality of the holes sectioned by the adjacent first indicators are placed on a trailing-end side of the long medium, a first ratio of a spacing between the plurality of the holes and a unit length of the long medium and a second ratio of a difference between a spacing between the first indicators and a spacing between the second indicators and a change amount of a length of the long medium indicated by this difference are approximately equal to each other, the second indicators are provided to a side of the trailing-end holes, and each gradually come closer to the leading-end hole that pairs up with the trailing-end hole as the long medium runs toward a trailing end, a spacing between the leading-end hole and the second indicator is approximately proportional to a remaining amount of the long medium, and the remaining amount of the long medium is visually grasped by comparing a distance from the first indicator to the second indicator with the number of the plurality of holes, the image forming apparatus comprising: first detecting means for detecting the first indicator of the long medium; and second detecting means for detecting the second indicator.
 11. The image forming apparatus according to claim 10, further comprising: a control unit, wherein the control unit calculates the spacing between the first indicators and the second indicators from the position of the first indicators detected by the first detecting means and the position of the second indicators detected by the second detecting means, and wherein the control unit calculates the remaining amount of the long medium from the calculated spacing.
 12. The image forming apparatus according to claim 11, wherein the control unit compares the detected remaining amount of the long medium and the length of the long medium according to output of input data, and wherein when the detected remaining amount of the long medium is shorter than the length of the long medium according to the output of the input data, the control unit stops the operation.
 13. The image forming apparatus according to claim 12, further comprising: a notifying means for notifying a shortage of the long medium when the remaining amount of the long medium is shorter than the length according to the output of the input data.
 14. The image forming apparatus according to claim 13, wherein the control unit detects a change amount of the remaining amounts at a plurality of points of the long medium during the conveyance operation, compares each calculated change amounts, determines whether the change amount is within certain or prescribed amounts, and determines the conveyance is insufficient when the control unit determines that the change amount is not within certain or within prescribed amounts.
 15. The image forming apparatus according to claim 14, wherein when the control unit determines that conveyance is insufficient, the control unit stops the operation of the image forming apparatus or causes the user to be notified by the notifying means.
 16. An image forming apparatus for outputting to a long medium having an adhesive sheet having a first adhesive side edge part and a second adhesive side edge part, the adhesive sheet temporarily adhered to a release sheet having a first release side edge part and a second release side edge part, the long medium comprising: a plurality of holes equidistantly provided on a straight line on both the first side edge part and the second side edge part in a longitudinal direction of the release sheet or all of the first adhesive side edge part and the second adhesive side edge part of the adhesive sheet and the first release side edge part and the second release side edge part of the release sheet; a plurality of first indicators repeatedly given on at least one of the first or second release side edge parts of the release sheet or all of the first adhesive side edge part and the second adhesive side edge part of the adhesive sheet and the first release side edge part and the second release side edge part of the release sheet on a straight line at spacings of an integral multiple of spacings of the plurality of holes; and a plurality of second indicators for equidistantly sectioning the plurality of holes, the plurality of second indicators are repeatedly given on at least one of the side edge parts of the release sheet or all of the first adhesive side edge part and the second adhesive side edge part of the adhesive sheet and the first release side edge part and the second release side edge part of the release sheet on a straight line different from a row of the first indicators at spacings shorter than spacings of the first indicators, wherein the plurality of holes, the plurality of first indicators, and the plurality of second indicators are provided approximately in parallel to one another, a spacing between a leading-end hole and a trailing-end hole between the pair of first indicators indicates a reference length of the long medium, the leading-end hole of the plurality of holes sectioned by the adjacent first indicators are placed on a tip side of the long medium and the trailing-end hole of the plurality of the holes sectioned by the adjacent first indicators are placed on a trailing-end side of the long medium, a first ratio of a spacing between the plurality of the holes and a unit length of the long medium and a second ratio of a difference between a spacing between the first indicators and a spacing between the second indicators and a change amount of a length of the long medium indicated by this difference are approximately equal to each other, the second indicators are provided to a side of the trailing-end holes, and each gradually come closer to the leading-end hole that pairs up with the trailing-end hole as the long medium runs toward a trailing end, a spacing between the leading-end hole and the second indicator is approximately proportional to a remaining amount of the long medium, and a change in the remaining amount is visually grasped by comparing the number of holes between the first indicator and the second indicator with a mark part, the image forming apparatus comprising: first detecting means for detecting the first indicator of the long medium; and second detecting means for detecting the second indicator.
 17. The image forming apparatus according to claim 16, further comprising: a control unit, wherein the control unit calculates the spacing between the first indicators and the second indicators from the position of the first indicators detected by the first detecting means and the position of the second indicators detected by the second detecting means, and wherein the control unit calculates the remaining amount of the long medium from the calculated spacing.
 18. The image forming apparatus according to claim 17, wherein the control unit compares the detected remaining amount of the long medium and the length of the long medium according to output of input data, and wherein when the detected remaining amount of the long medium is shorter than the length of the long medium according to the output of the input data, the control unit stops the operation.
 19. The image forming apparatus according to claim 18, further comprising: a notifying means for notifying a shortage of the long medium when the remaining amount of the long medium is shorter than the length according to the output of the input data.
 20. The image forming apparatus according to claim 19, wherein the control unit detects a change amount of the remaining amounts at a plurality of points of the long medium during the conveyance operation, compares each calculated change amounts, determines whether the change amount is within certain or prescribed amounts, and determines the conveyance is insufficient when the control unit determines that the change amount is not within certain or within prescribed amounts.
 21. The image forming apparatus according to claim 20, wherein when the control unit determines that conveyance is insufficient, the control unit stops the operation of the image forming apparatus or causes the user to be notified by the notifying means. 